An experimental animal model for Aspergillus parasiticus disease has been developed. Since small amounts of aflatoxin are excreted in the urine from infected rats and aflatoxin is also found in hyphae present in tissues, this model will provide tissues, body fluids and excretion products which can be used as substrates to help overcome some of the technical difficulties encountered in both the peroxidase-linked immunosorbent analysis and the peroxidase-linked immunocytochemical technique developed in this laboratory to detect aflatoxin in picogram quantities. The rats which survive the aspergillotoxicosis will be studied to see if liver cancer develops as a result of such exposure to aflatoxin. An investigation of the influence of steroidal hormones on the in vitro and in vivo synthesis of aflatoxin will be conducted. Possible mechanisms of the pathological action of aflatoxins will be investigated by studying hormone-aflatoxin interactions at the cytoplasmic and nuclear receptor sites. Studies will be undertaken to develop new immunizing procedures with the aflatoxin antigen. The development of immunological assays for aspergillic acid will be initiated.